Arc welding



Nov. 8, 1927.

1,648,683 G. T. HERALD ARC WELDING Filed Oct. 25. 1924' Inventor:

Gardner T. Herald,

His Attorn ey.

Patented Nov. 8, 1927.

UNITED STATES PATENT OFFICE.

GARDNER '1. HERALD,

ARC WELDING.

Application filed October 25, 1924. serm no. 745,928.

bottom of the opening between their meeting edges. The facility withwhich this result is accomplished depends on the heat conductingproperties both of the parts to be welded and of the backing plate ormember upon which the parts to be welded are laid or clamped. Thus, inthe case of a backing the heat is rapidly abstracted from the partsbeing welded and the weld may be defective between the edges which liedirectly upon the backing strip. In accordance with my invention, thisdifiioulty is avoided by rou hening or knurling the surface of the bacing member to produce a plurality .of projections and depressions whichform air pockets which serve to retard the transfer of heat between thework and the backing member. a

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawing and itsscope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1 shows my invention as utilized inwelding a flange to a pipeor nozzle; and Fig. 2 shows it as utilized inwelding together a plates. 40 Fig. 1 shows a nozzle or pipe 1 arrangedat one end to have its edge in juxtaposition to the inner peripher of aflange which, toether with the 'nozz e 1, is supported on a ackingplate'3. .As indicated by the drawv ing, the surface of the backingplate 3 is roughened or knurled to prevent the ready transmission ofheat between the backin plate 3 and the metal parts 1 and 2 whic are tobe welded together. Heat for performing the from an are formed betweenthe electrode 4 and-the parts to be welded together. The

invention relates to electric arc weldlate made of copper, for example.

pair of metal vided with a knurled welding operation is derived circuitthrough which current is transmitted to this are 1s indicated by thelead 5 and the ground 6. The metal 7 by which the parts 1 and 2 arefused together may be deposited from the electrode 4. Fig. 2 differsfrom Fig. 1 merely in that it shows the work to be welded as comprisinga pair of plate members'8 and 9.

While I have referred .to the backing member as having a knurledsurface, it is apparent that the backing member may have its surfaceotherwise treated to facilitate the formation of heat insulating pocketsbetween the work and backing plate. I therefore aim to cover by theappended claims any arrangement in which the backing plate is roughenedto form pockets by which a substantial measure of heat insulation isafforded between the work and the backing member.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. The method of joining the edges of metal parts which comprisespositioning said edges injuxtaposition, backing said metal parts alongsaid edges at a plurality of closely adjacent metallic contact points ofsmall area, and directing a welding are against said edges to unite themby fusion.

2. The method of electric arc welding which comprises maintaining an arebetween the work as one electrode and a fusible metallic pencil as theother electrode, while backing the work upon a plurality of closelyadjacent spaced metallic points.

3. A backing member for electric arc welding having a knurledworksupporting surface.

4. A backing member for electric arc welding comprising a copper memberprosurface for the purpose described.

5. A metallic backing member for electric arc welding provided with awork supporting surface portion of low heat conducting capacity.

6. A metallic backing member for electric arc welding having its worksupporting surface roughened.

In witness whereof, I have hereunto set my hand this 20th da of October,1924.

' GARD R T. HERALD.

